Considering all the possibilities, factory error, while certainly possible, is less probable than operator error. The most likely operator error is improper seating, which I (and probably all of us) have done more than a few times on our way towards getting good at this hobby. Usually, a second strike will tell you if that is the problem. If that is not it, I would look at contamination. Are you lubing your cases? With what? Do you let them dry? Try a batch with no case lube at all, at least if making handgun loads. Do you clean your press? How, and with what? Oil, and especially penetrating oil or solvent will kill primers permanently. Clean the press with alcohol, then blow it with compressed air (you can buy cans at computer stores). You'll get there.